Process and apparatus for recovering bitumen from bituminous sands

ABSTRACT

A process and apparatus for the separation of the sand component from an admixture of bitumen or oil, sand and water such as bituminous sands derived from the Athabasca tar sands located in the Province of Alberta, Canada in which a mass of the admixture is compacted and directed against a displaceable oleophilic surface to apply a thin layer to such surface and driving the surface at a rate sufficient to dislodge the sand from the applied layer and recovering the bitumen-enriched residue adhered to the surface.

United States Patent 1 1 1 on 3,891,550 Gray et al. June 24, 1975 [54] PROCESS AND APPARATUS FOR 1.550.293 8/1925 Walker 210/386 OVE [N B TU EN FROM 1,791,797 2/1931 Clark 208/11 EIETQIMINIZUSSJNDQJ 2,790,750 4/1957 Eyre l96/l55 X 3,068,167 12/1962 White [76] Inventors; Frank Alexander Gray; John Adam 3,070,541 12/1962 Price 210/73 X Gray, both of 169 Fifth St., gi Omano Canada Msv Primary Examiner-Samih N, Zaharna Assistant ExaminerR0bert H. Spitzer [22] Filed: Dec. 17,1973

I21] Appl. No.: 425,085

57 ABSTRACT Related US. Application Data [63] Continuation of Ser. No. 194,304, Nov. 1, 1971, A process and apparatus for the separation of the sand abandoned. component from an admixture of bitumen or oil, sand and water such as bituminous sands derived from the 1 1 u /6 196/ 155; 208/ l Athabasca tar sands located in the Province of Al- 210/77; 210/397; 210/402 berta, Canada in which a mass of the admixture is [51] Int. Cl B01d 33/02 compacted and directed against a displaceable oleo- [58] Field of Search 19 /1 5, 208/1 philic surface to apply a thin layer to such surface and driving the surface at a rate sufficient to dislodge the 24, 402 sand from the applied layer and recovering the bitumen-enriched residue adhered to the surface. (56] References Cited UNITED STATES PATENTS 20 Claims, 3 Drawing Figures 581,908 5/1897 Gent et a1 209/46 X PATENTEI] JUN 2 4 I975 FIGB 1 PROCESS AND APPARATUS FOR RECOVERING BITUMEN FROM BITUMINOUS SANDS This application is a continuation of Ser. No. 194,304, filed Nov. 1, 1971, now abandoned.

BACKGROUND This invention relates to improvements in the processing of mined bituminous sand deposits for the recovery of bitumen therefrom, particularly bituminous sand deposits of the character of the Athabasca tar sands located in the Athabasca region of the Province of Alberta, Canada, which have been described in published literature as constituting essentially an admixture of bitumen, sand, clay and water.

The sand component of the Athabasca tar sand de posit has been described as predominantly quartz in the form of rounded or subangular particles each of which is wet with a film of water and in turn enveloped by a film of bitumen which also somewhat fills the void volume among the sand grains, with the balance of the void volume being filled with connate water and occasionally with a small volume of gas usually air or sometimes methane.

Two known methods for the recovery of bitumen from bituminous sand deposits are described as the cold water method" and the hot water method.

The cold water method consists basically in adding an oil diluent, water, an alkaline reagent and a wetting agent to bituminous sand, disintegrating the mixture in a pebble mill, diluting with water, separating the major part of the sand in a classifier and settling out water and finely divided inorganic matter in thickeners, and recovering the bitumen and diluent by flotation.

The function of the diluent is to combine with the bitumen decreasing its viscosity so that it can be separated from the sand and decreasing its specific gravity so that it rises to the surface of the water.

In the "hot water method the mined admixture is mixed with water and steam to approximately l80F to form a pulp the pH of which is preferably maintained within a range of 8.0-8.5.

After additional water is added to the pulp it is screened and transferred to a separation cell where the bitumen is taken off in the form of a froth emulsion with air, water and residual minerals, for further processing.

More recently it has been shown that agitation with water at ambient temperatures of a mass of bituminous sand of the character mentioned, produces bituminous agglomerates and relatively clean sand.

OBJECTS OF THE INVENTION The principal object of this invention is to reduce the costs and improve efficiency in the recovery of bitumen from such bituminous sand deposits by simplifying the primary steps of separation of the sand component from a mass of the mined admixture to yield a bitumen enriched residue suitable for further processing.

Another important object is to provide a process applicable to such admixtures over a range of compositions found in bituminous sand deposits such as the Athabasca tar sands.

More particularly it is an object of this invention to provide a process which utilizes equipment derived largely from a combination of elements of conventional design and readily adaptable for small or large installations.

FEATURES OF THE INVENTION The principal feature of this invention resides in providing a process for the mechanical separation of the sand component from the admixture in which a mass of the mined admixture sufficiently compacted, is directed against an oleophilic surface displaceable generally transversely to the direction of the mass in a manner such that a portion of the mass is continuously applied to such surface in the form of a thin layer with the surface being driven at a rate of displacement sufficient to dislodge the sand from the applied layer and recovering the bitumen enriched residue adhered to the oleophilic surface at a point remote from the region of application and affter dislodgment of the sand.

More particularly where a mass has a low concentration of water or its composition is variable, mixing or agitation of the mass with water at ambient temperatures to thoroughly wet the mixture is desirable before compacting and directing the mass against the displaceable oleophilic surface of the apparatus.

Further it is a feature of this invention to enhance the separation of the sand component and adherence of the bitumen to the oleophilic surface by urging the applied thin layer against the displaceable surface throughout a portion of its travel beyond the region of its application to the surface and prior to the dislodgment of the sand.

In the preferred embodiment an oleophilic surface constituted by the outer axially extending surface of a cylindrical drum or roll is mounted for rotation and against such surface a mass of the admixture is adapted to be directed under pressure throughout an axially extending region thereof and in a generally radial direction, and regulated so that a thin layer is continuously applied, whereupon under the influence of the attraction of the bitumen for the oleophilic surface and centrifugal forces the sand component is separated from the admixture by dislodgment substantially immedi ately following the application of a layer of the mass to the oleophilic surface.

It is also a feature to provide a block, preferably of a resilient nature, to bear against the applied thin layer of admixture immediately following its application of the oleophilic surface which enhances the tendency of the bitumen-enriched residue to adhere to the oleophilic surface and increases the tendency of the sand to separate from the admixture under the influence of centrifugal forces thereby improving the efficiency.

DRAWINGS Other objects and features will become apparent upon reading the following specification in conjunction with the sheet of drawings in which FIG. 1 is a side elevational and partly vertical crosssectional view with supporting structures broken away, of typical apparatus by which the process embodying the invention may be implemented;

FIG. 2 is a plan view of the apparatus of FIG. 1', and

FIG. 3 is a perspective view partly broken away, of

the bearing block element of the apparatus illustrated in FIG. 1.

APPARATUS In accordance with the invention a cylindrical roll 10 having an axle 12 is mounted for rotation on a suitably anchored base, not illustrated, with its axially extending circumferential surface 14 exposed for contact.

The surface 14 of roll is oleophilic. In the preferred embodiment the oleophilic surface is presented by a moulded band 16 of neoprene rubber which, in addition, has the attributes of being resilient and resistant to deterioration which under the conditions encountered are factors promoting a successful continuous process.

A suitable motor and drive connection, not illustrated, are provided for driving the roll 10 in the direction of arrow 18 at selected angular velocities.

Mounted adjacent roll 10 and suitably anchored on support structure, not illustrated, is a charging apparatus 20, constituting a charging station which includes a hopper 22 for continuously delivering a mass of the admixture to the surface 14 of the roll 10 through a lowr channel formation or chute 24.

in the preferred embodiment illustrated, the channel formation 24 extends generally radially of the axle l2 and is inclined uniformly downwardly from hopper 22 terminating at its lower end in an orifice 26 arranged in closely spaced relation to the surface 14 of roll 10 leaving a small gap 27.

Slidably mounted within channel formation 24 is a ram or piston 28, which may be reciprocated by a suitable drive, not illustrated, in the direction of the arrows indicated at 30.

When the ram 28 is reciprocated it displaces the mass of admixture supplied by hopper 22 along channel 24 for discharge through orifice 26 and against the surface 14 of roll 10.

in the preferred embodiment illustrated in FlG. l the charging apparatus includes a depending guide formation 32 inclined downwardly and below channel formation 24 and terminating as at 34 in closely spaced relation to the surface 14 of roll 10.

Slidably supported within the depending guide formation 32 is a block 36 which under the urging of a suitably resilient spring formation 38 extends beyond depending guide formation 34 and bears against the surface 14 of roll 10.

The material of block 36 in the preferred embodiment is neoprene rubber.

Neoprene block 36 is preferably incised throughout a portion of its extent in the pattern illustrated at 40 in FIG. 2. The block 36 is mounted so that the end surface 42, provided with a slight curvature corresponding to the curvature of the roll 10, is adapted to bear lightly against the layer of admixture to be applied to surface 14 to achieve a brush-like resilient abrasive action.

A suitable hopper or receptacle 44 is mounted below charging apparatus 20 to collect sand to be separated from the admixture.

A scraper 46 in the form of a knife edge is preferably adjustably mounted within a supporting framework, not illustrated, at a point remote from the point of application of the admixture to the surface 14 of roll 10, to bear against surface 14 thereby constituting a scraping station to strip the adhered residue therefrom and in addition a hopper or receptacle 48 is provided to collect the stripped residue for further treatment.

In the illustrated embodiment the axis of rotation of roll 10 and axle 12 is horizontal. According to the invention roll 10 and axle 12 can be mounted for rotation about a vertical axis with appropriate modification of the associated structures constituting the charging station and the scraping station.

Further it is to be understood that while only one charging station and scraping station have been illustrated and described in relation to the single roll the number of charging stations and scraping stations that can be established will vary in accordance with the diameter of the roll selected and the space requirements.

In the case where the axis of rotation of the roll and the axle is vertical the sequence of charging station followed by scraping station can be established throughout the full circumference of the roll, with the number being limited only by the diameter and by the space available for installation of the peripheral charging apparatus, scraping apparatus and associated structures.

PROCESS Where bituminous sand mined from the deposit contains hard lumps or rocks, these should be removed by known procedures.

If the percentage weight of water of the admixture as mined is low it is desirable to introduce water at ambient temperatures in sufficient quantity and agitate the admixture to thoroughly wet the admixture.

Should excess water be added it should be removed, for example by subjecting the mass to compressive forces, for the mass must have sufficient degree of compactness to bear against the oleophilic surface 14 of roll 10 upon extrusion from the orifice 26 of the charging apparatus 20.

An admixture of preferably uniform consistency containing essentially bitumen, sand, clay and sufficient water is delivered through suitable equipment to hopper 22 as shown in FIG. 1.

Under gravitational forces and the action of reciprocable ram 28 the mass indicated at 50in FIG. 1 is delivered through lower channel formation 24 and extruded through orifice 26 to bear against oleophilic surface 14.

With roll 10 driven in the direction of the arrow 18 the abrading action of the surface 14 against the extruded mass 50 and the close spacing of orifice 26 to the surface 14 results in the application of a thin layer of the mass onto the oleophilic surface 14 continuously.

With a roll 10 including the molded band 16 of neoprene of approximately 5 inches in diameter, and operated at an angular velocity of 2500 rpm. at ambient temperatures of between 60 to "F and with a gap 27 of the order of 0.020 inches immediately upon the mass 50 being urged against oleophilic surface 14 to apply a thin layer thereto, the wetted sand particles appeared to be continuously discharged from the layer of the mass in a somewhat tangential direction probably due to centrifugal forces and downwardly under gravitational forces in a substantially bitumen-free state as indicated generally at 52 leaving a bitumen-enriched layer 54 clinging to the oleophilic surface 14.

Bituminous layer 54 in its tacky state may be readily stripped from the surface 14 by the knife edge of scraper 46 for discharge into receptacle 48 for further processing.

Preferably, in accordance with the invention, the face 42 of neoprene block 36 is brought to bear continuously under the action of the spring formation 38 against the applied layer of the mass in that region 56 of the surface 14 immediately adjacent and below the region of application of the mass.

With such latter modification it has been observed that the percentage of the residual bitumen in the separated sand is decreased and the percentage of the residual sand in the enriched bitumen layer is decreased as compared with operations in which neoprene block 36 is not employed thereby increasing the efficiency of the operation.

Under continuous operation at ambient temperatures it has been observed that the temperature of the oleophilic surface 14 increases to the degree such that the recovered bitumen-enriched residue 54 loses its tackiness and under the influence of centrifugal forces leaves the surface 14.

Accordingly in those circumstances the surface 14 must be cooled either continuously or intermittently to a temperature below the level at which the bitumenenriched layer loses its tackiness. In a commercial installation the temperature of the oleophilic surface 14 or its equivalent can be controlled by a suitable cooling system in order that continuous operation over long periods may be achieved.

While the preferred process and apparatus embodying the invention have been described and illustrated modifications or variations may be undertaken by those persons skilled in this field without departing from the spirit and the scope of the invention as defined in the appended claims.

What is claimed is:

1. In a process for recovering bitumen from an admixture of bitumen, sand and water derived from a bituminous sand deposit of the type described, the steps of a. compacting a mass of the admixture,

b. directing the compacted mass against an oleophilic surface displaceable generally transversely to the direction of application of the mass,

c. constraining the mass against the surface in the region of application only to apply a thin layer of the mass thereonto,

d. driving the surface at a rate of displacement sufficient to and in a direction to apply the layer and to dislodge sand from the applied layer of the admixture following release from constraint and e. recovering the residue adhered to the surface.

2. A process according to claim 1 wherein a raw admixture derived from a bituminous sand deposit of the type described is first mixed with additional water to thoroughly wet the admixture prior to the compacting of same.

3. A process according to claim 1 wherein the applied layer is resiliently urged against the surface throughout a portion of its travel following its application to the surface and prior to dislodgement of the sand.

4. In a process for recovering bitumen from an admixture of bitumen, sand and water derived from a bitimunous sand deposit of the type described, the steps of a. compacting a mass of the admixture,

b. directing the compacted mass against an outer endless displaceable oleophilic surface having an axis of revolution,

c. constraining same in the region of application only in a manner such that a portion of the mass continuously bears against the surface to apply a thin layer of the mass thereonto,

d. driving the surface at an angular velocity sufficient to and in a direction to apply the layer and to dislodge sand from the applied layer of admixture following release from constraint and e. recovering the residue adhered to the surface.

5. A process according to claim 4 wherein a raw admixture derived from a bituminous sand deposit is first mixed with additional water to thoroughly wet the admixture prior to the compacting of same.

6. A process according to claim 4 wherein the applied layer is resiliently urged against the surface throughout a portion of its travel following its application to the surface and prior to dislodgment of sand.

7. A process according to claim 4 in which the direction of application of the mass onto the surface is substantially radial in relation to the axis of revolution of the surface.

8. A process according to claim 4 in which the adhered residue is recovered by scraping same from the surface at a station removed from the region of application of the mass to the surface after dislodgment of sand.

9. ln apparatus for separating sand from an admixture of oil or bitumen sand and water derived from a bituminous sand deposit of the type described and recovering an oil or bitumen enriched residue therefrom, the combination of a. means presenting a smooth endless oleophilic surface of substantial width;

b. means for delivering a mass of admixture against a selected region of said surface, including a charging apparatus terminating in a discharge orifice;

c. means for supporting said discharge orifice in closely spaced relation to said surface in the region of application of the mass to said surface, thereby defining a restricted passageway to constrain the mass to be applied thereonto to a thin layer of substantially uniform thickness;

d. means associated with said charging apparatus for displacing the mass therewithin to said surface through said discharge orifice;

e. means for continuously displacing said surface at a rate sufficient and in a direction to constrain the mass and apply the thin layer and to dislodge sand from the applied layer respectively after emerging from said restricted passageway; and

f. means for removing the adhered residue of the mass from said surface.

10. Apparatus according to claim 9 in which said smooth endless oleophilic surface is presented by the external axially extending surface of a roll of generally cylindrical configuration.

11. Apparatus according to claim 10 in which said smooth endless oleophilic surface is presented by a layer of neoprene rubber.

12. Apparatus according to claim 9 wherein said means associated with said charging apparatus for displacing the mass comprises displaceable ram means.

13. Apparatus according to claim 9 in which means are provided for urging the applied thin layer against said surface throughout the region next adjacent the region of application of the mass to said surface and for a short distance therebeyond.

14. Apparatus according to claim 13 in which said urging means comprises a yieldable block of neoprene rubber, with the portion adapted to bear against the applied layer being incised in a pattern to present a brush like structure thereto.

15. Apparatus according to claim 9 wherein the layer thinness is limited to substantially 0.020 inches or less.

16. In apparatus for separating the oil or bitumen from an admixture of oil or bitumen sand and water derived from a bituminous sand deposit of the type described in recovering an oil or bitumen enriched residue therefrom, the combination of a. a generally cylindrical roll presenting an external axially extending smooth endless oleophilic surface of substantial width;

b. means supporting said roll for rotation about its axis;

c. charging means including a charging apparatus terminating in a discharge orifice for delivering a mass of admixture to said surface through said discharge orifice throughout a selected region of said surface and extending generally transversely thereof;

d. means for supporting said charging means to present said discharge orifice in closely spaced relation next adjacent said surface to define a restricted passageway for constraining the application of the mass to be applied against said surface to a thin layer of the order of one sand grain thickness;

e. means associated with said charging means for displacing the mass therewithin to said surface through said discharge orifice;

f. means for rotating said roll at a rate sufficient to and in a direction to subject the mass to said constraining means to apply a thin layer and dislodge sand from the applied layer after release from said restricted passageway; and

g. means associated with said surface for removing the adhered bitumen-enriched residue therefrom.

17. In a process for recovering bitumen from a mass of an admixture of bitumen, sand and water derived from a bituminous sand deposit of the type described, the steps of delivering the mass to a selected region of a displaceable oleophilic surface and constraining same in the selected region only, in a manner such that a layer of the mass of substantially uniform thinness is applied continuously thereonto, driving said surface at a rate of displacement sufficient to and in a direction to apply the thin layer and to dislodge sand from the applied layer and recovering the residue adhered to the surface.

18. [n a process according to claim 17 wherein the applied thin layer is urged against the surface for a short distance beyond said selected region of application.

19. A process according to claim 17 wherein the thinness of the layer is of the order of 0.020 inches or less.

20. A process according to claim 17 wherein water is added to the mass to achieve sufficient wetness throughout prior to delivery of the mass against the selected region of the displaceable oleophilic surface. 

1. IN A PROCESS FOR RECOVERING BITUMEN FROM AN ADMIXTURE OF BITUMEN, SAND AND WATER DERIVED FROM A BITUMINOUS SAND DEPOSIT OF THE TYPE DESCRIBED, THE STEPS OF A. COMPACTING A MASS OF THE ADMIXTURE, B. DIECTING THE COMPACTED MASS AGAINST AN OLEOPHILIC SURFACE DISPLACEABLE GENERALLY TRANSVERSELY TO THE DIRECTION OF APPLICATION OF THE MASS, C. CONSTRAINING THE MASS AGAINST THE SURFACE IN THE REGION OF APPLICATION ONLY TO APPLY A THIN LAYER OF THE MASS THEREONTO, D. DRIVING THE SURFACE AT A RATE OF DISPLACEMENT SUFFICIENT TO AND IN A DIRECTION TO APPLY THE LAYER AND TO DISLODGE SAND FROM THE APPLIED LAYER OF THE ADMIXTURE FOLOWING RELEASE FROM CONSTRAINT AND E. RECOVERING THE RESIDUE ADHERED TO THE SURFACE.
 2. A process according to claim 1 wherein a raw admixture derived from a bituminous sand deposit of the type described is first mixed with additional water to thoroughly wet the admixture prior to the compacting of same.
 3. A process according to claim 1 wherein the applied layer is resiliently urged against the surface throughout a portion of its travel following its application to the surface and prior to dislodgement of the sand.
 4. In a process for recovering bitumen from an admixture of bitumen, sand and water derived from a bitimunous sand deposit of the type described, the steps of a. compacting a mass of the admixture, b. directing the compacted mass against an outer endless displaceable oleophilic surface having an axis of revolution, c. constraining same in the region of application only in a manner such that a portion of the mass continuously bears against the surface to apply a thin layer of the mass thereonto, d. driving the surface at an angular velocity sufficient to and in a direction to apply the layer and to dislodge sand from the applied layer of admixture following release from constraint and e. recovering the residue adhered to the surface.
 5. A process according to claim 4 wherein a raw admixture derived from a bituminous sand deposit is first mixed with additional water to thoroughly wet the admixture prior to the compacting of same.
 6. A process according to claim 4 wherein the applied layer is resiliently urged against the surface throughout a portion of its travel following its application to the surface and prior to dislodgment of sand.
 7. A process according to claim 4 in which the direction of application of the mass onto the surface is substantially radial in relation to the axis of revolution of the surface.
 8. A process according to claim 4 in which the adhered residue is recovered by scraping same from the surface at a station removed from the region of application of the mass to the surface after dislodgment of sand.
 9. IN APPARATUS FOR SEPARATING SAND FROM AN ADMIXTURE OF OIL OR BITUMEN SAND AND WATER DERIVED FROM A BITUMINOUS SAND DEPOSIT OF THE TYPE DESCRIBED AND RECOVERING AN OIL OR BITUMEN ENRICHED RESIDUE THEREFROM, THE COMBINATION OF A. MEANS PRESENTING A SMOOTH ENDLESS OLEOPHLIC SURFACE OF SUBSTANTIAL WIDTH;
 10. Apparatus according to claim 9 in which said smooth endless oleophilic surface is presented by the external axially extending surface of a roll of generally cylindrical configuration.
 11. Apparatus according to claim 10 in which said smooth endless oleophilic surface is presented by a layer of neoprene rubber.
 12. Apparatus according to claim 9 wherein said means associated with said charging apparatus for displacing the mass comprises displaceable ram means.
 13. Apparatus aCcording to claim 9 in which means are provided for urging the applied thin layer against said surface throughout the region next adjacent the region of application of the mass to said surface and for a short distance therebeyond.
 14. Apparatus according to claim 13 in which said urging means comprises a yieldable block of neoprene rubber, with the portion adapted to bear against the applied layer being incised in a pattern to present a brush-like structure thereto.
 15. Apparatus according to claim 9 wherein the layer thinness is limited to substantially 0.020 inches or less.
 16. In apparatus for separating the oil or bitumen from an admixture of oil or bitumen sand and water derived from a bituminous sand deposit of the type described in recovering an oil or bitumen enriched residue therefrom, the combination of a. a generally cylindrical roll presenting an external axially extending smooth endless oleophilic surface of substantial width; b. means supporting said roll for rotation about its axis; c. charging means including a charging apparatus terminating in a discharge orifice for delivering a mass of admixture to said surface through said discharge orifice throughout a selected region of said surface and extending generally transversely thereof; d. means for supporting said charging means to present said discharge orifice in closely spaced relation next adjacent said surface to define a restricted passageway for constraining the application of the mass to be applied against said surface to a thin layer of the order of one sand grain thickness; e. means associated with said charging means for displacing the mass therewithin to said surface through said discharge orifice; f. means for rotating said roll at a rate sufficient to and in a direction to subject the mass to said constraining means to apply a thin layer and dislodge sand from the applied layer after release from said restricted passageway; and g. means associated with said surface for removing the adhered bitumen-enriched residue therefrom.
 17. In a process for recovering bitumen from a mass of an admixture of bitumen, sand and water derived from a bituminous sand deposit of the type described, the steps of delivering the mass to a selected region of a displaceable oleophilic surface and constraining same in the selected region only, in a manner such that a layer of the mass of substantially uniform thinness is applied continuously thereonto, driving said surface at a rate of displacement sufficient to and in a direction to apply the thin layer and to dislodge sand from the applied layer and recovering the residue adhered to the surface.
 18. In a process according to claim 17 wherein the applied thin layer is urged against the surface for a short distance beyond said selected region of application.
 19. A process according to claim 17 wherein the thinness of the layer is of the order of 0.020 inches or less.
 20. A process according to claim 17 wherein water is added to the mass to achieve sufficient wetness throughout prior to delivery of the mass against the selected region of the displaceable oleophilic surface. 